Ben Carson has shot into the lead of the Republican presidential race, ousting Donald Trump, the eccentric and egocentric billionaire, from the top spot.

The retired neurosurgeon now has a 29pc approval rating, the highest level of voter support registered for any Republican candidate in the 2016 election race, according to a new NBC News/Wall Street Journal poll.

Mr Trump, the larger-than-life real-estate mogul and television celebrity, dominated the early part of the campaign.

For several months since June, 'The Donald' had seemed unbeatable, rising inexorably in the polls despite a litany of scandalous, often racist-sounding, remarks that would have long killed the ambitions of a regular career politician.

Meanwhile, Mr Carson, a subscriber to the Seventh-Day Adventist doctrine that believes in the End Of Times, kept his cool.

While Mr Trump loudly promised the American people "great deals" that would restore the nation's status and power across the world, the good doctor put in more soft-spoken appearances, essentially asserting that if he could conduct brain surgery he could certainly operate well in the White House.

The new poll confirmed reports that Mr Carson's approach was finally working.

The former television celebrity was placed second in the poll, with 23pc.

He and Mr Carson were still well clear of the rest of the field, reflecting the disillusionment that Republican voters have expressed with established politicians.

Marco Rubio, the younger darling of the Republican establishment came in third at 11pc after a strong debate performance last week.

Ted Cruz, the evangelical Texas senator polled at 10pc, and Jeb Bush, the once-presumed favourite, continued to languish in the doldrums with only 8pc.

With neither Mr Trump or Mr Carson having ever held elected office, the two have competed to see who can best define themselves as the "outside" candidate that the Republican electorate appears to be looking for.

Mr Trump has gone on the offensive - what he does best - by accusing Mr Carson of not being sufficiently "smart" to become commander-in-chief.

The revenge tactic of Mr Carson, the neurosurgeon who is best known for separating twins who were joined at the head, was to be calm.